I have an iCute S901-5G1-BB http://icute.com.tw/english/S901.html with two thermaltake iCage's - 120mm fans in blue on the front blowing cold air in, with a single 120mm fan expelling. I know sharkoon do a rebadged version of this...

This qualifies as under £50 as I bought it for £29.99 and the two cages were £20 from ebay...